Enhanced MIMO subspace detection with interference cancellation

A low-complexity detection algorithm is proposed for Multiple-Input Multiple-Output (MIMO) systems with many transmit and receive antennas. We involve QR Decomposition (QRD) to triangularize the effective MIMO channel matrix so that several MIMO sub-systems can be individually established, which allow detecting several (possibly overlapping) groups of data streams separately. This method is referred to as MIMO Overlapped Subspace Detection (OSD). Further, we propose an OSD based non-iterative (i.e., without feedback from an outer channel decoder) Interference Cancellation (IC) approach where some streams are cancelled out as reliable interference. Link layer simulations for an 8×8 configuration show that this algorithm not only inherits the feature of OSD, yielding a scalable performance/complexity trade-off, but can also closely approach the MIMO ergodic capacity.